Metal-cutting tool.



- F. Bi BO GORSELSKI.

METAL-CUTTING TOOL.

Patented July 22, 1913:

FRANK E. BOGOBSELSKI, OF RICHIIEOND, VIRGINIQ.

METAL-CUTTING TOOL.

Specification of Letters Patent.

Patented July 22, 1913.

Application filed January 21, 1913. Serial No. 743,236.

To all :whom it may concern Be it known that I, FRANK E. BOCORSEL- SKI, of Richmond, in the county of Henrico and State of Virginia, have invented a certain new and useful Improvement in Metal- Cutting Tools, of which improvement the following is a specification.

The object of my invention is to provide a construction whereby the cost of maintenance of high speed taps, reamers, or other peripheral cutting tools may be reduced, and the depth of cut thereof accurately regulated as desired. v

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a view, partlyin elevation and partly in longitudinal central section, illustratin my invention as applied in connection with a stay bolt tap; Fig: 2, an end View, as seen from the left; and,Figs. 3 and 4, transverse sections, on the lines a a and b 6, respectively, of Fig. 1.

My invention is herein exemplified as applied in connection with a stay bolt reamer, 1, used for cutting internal threads in two firebox sheets, A. and B, of a locomotive boiler, which reamer is provided with a plurality of .peripheral screw cutting threads, 1, of the usual form. In the practice of my invention, I provide a mandrel, 2, of hardened and ground tool steel, which is provided, at one end, with a squared hub, Q, for the application of means by which it may be rotated, and is externally threaded for a portion of its length adjoining said hub. A longitudinal, groove, 2, is cut in the'mandrel, for a purpose hereinafter described, and the mandrel is detachably connected to the reamer by means of a tongue,

2 on the mandrel, at the end of its external thread farther from the hub, said tongue engagmg a corresponding transverse slot,

1", in the adjacent end of the reamer. The.

relative location of the tongue and slot may, if preferred, be reversed, without involving any difference in principle or operative result. The mandrel extends through the reamer, and an externally threaded stem, 2, is formed on its opposite end, which thread engages a correspondin internal thread in the head, 3, of-a gui e'or pilot.

stem, 3, which fits in a hole in the boiler sheet farther from the reamer, in line axially with the latter, and serves to guide it when one or both of two holes in the sheets is or are to be threaded in line one with the other.

The depth of thecut made by the reamer which it surrounds. The end of the adjusting sleeve farther from the mandrel is brought to a thin ed e, which bears on the outer side of the boi er sheet in which the reamer operates.

An annular washer plate, 5, havmg an internal tongue, 5*, which engages the groove,

v2'-, of the mandrel; 2, is titted thereon, and is clamped to the adjacent end of the adjusting sleeve, 4, b av check nut, 6,,which engages the externa thread of the mandrel. In the operation of the appliance, the adjusting sleeve is screwed on the mandrel to be required by the desired depth of out, and

relative movement of the mandrel and adjusting sleeve is prevented by the engagesuch position in the length thereof as may ment of the tongue of the washer plate with the groove of the mandrel, when the Washer plate is brought to a tight bearing against the adjusting, sleeve by screwing up the check nut.

It will be obvious to those familiar with the art of cutting metal, that the wear of the mandrel and adjusting sleeve, both of which are made of hardened and ground steel, is practically negligible, while that of the cutting tool is rapid. The economy of renewal, as compared with ordinary practice, in which the mandrel and tool are integral, is therefore material. It will also be seen that the adjustment to desired depth of cut may be readily and accurately made, and be maintained without liability-to accidental displacement.

I claim as my invention and desire to se c'ure by Letters Patent 1. In combination with a cutting tool, a"

mandrel having its ends externally threaded and projecting through the cutting tool, means at the inner end of the threads at one end of the mandrel to detachably connect said mandrel to said cutting tool, a stop member threaded onto said last named end of the mandrel, and a pilot stem having'one end interiorly threaded and engaged with the other threaded end of the mandrel, said end of the pilot stem engaging the adjacentv end of the cutting tool and holding said" connecting means in locked position.

2. In combination with a-cutting tool, a mandrel arranged to have its ends project through the tool, a detachable connection between one end of the tool and the mandrel, the mandrel having its end at the opposite end of the tool exteriorly threaded, and a pilot stem threaded over said threaded'end of the mandrel and engaging said opposite end of the tool to hold the connection in locked position.

3. A mandrel comprising a central toolreceivingport-ion, a reduced threaded front end portion, and an enlarged threaded shank end portion, means at the junction of said central and shank end portions to engage the tool and hold it against rotation, a pilot stem adapted to be screwed on said front end against the end of the tool, a gage sleeve adapted to be screwed on said shank end so as to project forwardly around the tool, and means to clamp said sleeve in adjusted position.

4:. A mandrel having a threaded shank end portion of enlarged diameter, a central smooth portion'for the reception of a tubular cutting tool, and a threaded front end portion of reduced diameter, a pilot stem adapted to be screwed on to said reduced from end portion and thereby clamp the tool against the shoulder formed at the junction of the shank and central. portions, means to prevent the tool from rotating relatively to the mandrel and an adjustablestop sleeve screwed on said shank portion and projecting forwardly over the rear end of the tool-receiving portion.

L. B. SMITH, F. R. STEVENS. o 

